Mercury sphygmomanometer is a common medical device, in the measurement of blood pressure, to ensure human health plays a very important role. Because of its frequent use, poor maintenance, prone to failure. When pressurized, the mercury sphygmomanometer appears mercury column broken line or bubble phenomenon, the main reason for the storage of mercury in the bottle of mercury amount is too small caused by;
Additionally, the mercury column in the middle of the folder with air, the display tube wall or storage of mercury bottle is too dirty as well as the storage of mercury bottle air gap is also the reason;
Can be used to increase the amount of mercury, repeatedly pressurized a few times to exclude the air, clean the display tube or storage of mercury bottle, sealing sealing or replacing the mercury bottle to solve the problem. This situation will lead to the failure of inaccurate measurement value and large error, and the failure phenomenon is that when the switch of the sphygmomanometer is opened, the convex surface of the mercury column in the glass tube is lower than the zero scale line, or there is a broken column or bubbling phenomenon in the process of pressurization. At the same time in the sphygmomanometer box can be seen scattered mercury beads.
The mercury leakage is caused by human factors and sphygmomanometer component failure, the former is the main reason. Caused by mercury leakage sphygmomanometer components are common switch axis and mercury storage bottle seat, due to the two coincide with the bad, pressurized pressure leads to mercury spray. When this kind of failure occurs, should be timely replacement of the switch axis or storage mercury bottle base, and human factors refers to the improper use of health care workers.
Sphygmomanometer should be used should be tilted more than 450, so that the mercury back to the mercury storage bottle and then close the switch, the mercury off in the mercury storage bottle. Users often make the mistake of either not closing the switch, when closing the lid, the mercury in the glass tube leaks out from the upper end of the glass tube; either not tilted to close the switch, the zero mark below a section of mercury is blocked outside the mercury storage vial, stay in the glass tube of the indication of the value of the mercury after closing the lid, this part of the leakage of mercury; or the next time you use it, open the lid, the residual mercury in the mercury is not yet back to the zero mark with the mercury storage vial. Before returning to the zero mark and fusing with the mercury coming out of the mercury storage bottle, the user has begun to pressurize the mercury, resulting in the above section of mercury spraying out of the top of the glass tube.
In our work, we adopted a simple method of adding mercury: use a syringe with a needle, suck the right amount of mercury from the spare mercury, open the top cover of the sphygmomanometer, open the switch of the mercury storage vial, insert the needle from the small hole on the upper end of the glass tube on the pressure piece, gradually inject mercury, and gently vibrate the sphygmomanometer, so that the injected mercury and the mercury from the mercury storage vials of the mercury fusion, the amount of injected mercury to meet the zero position error. The amount of mercury injected is subject to the requirements of zero error, and a small-diameter needle should be used to avoid damage to the filter. Causes of zero misalignment is; too much or too little mercury; mercury storage bottle lid air permeability is poor; mercury or mercury storage bottle is too dirty; mercury storage bottle bottom bore channel is not smooth.
The solution is; adjust the amount of mercury, so that the zero position is aligned; with a needle in the mercury storage bottle on the lid pierced through a few small holes; filtering mercury; cleaning or replacement of the mercury storage bottle. Poor sensitivity is manifested in the uniform pressurization or depressurization, the mercury column rises and falls sluggishly, there is a jump phenomenon.
The main reason for the poor sensitivity is the mercury in the oxidation of mercury oxide generated by the dirty wall of the tube, hindering the sensitive rise and fall of the mercury column;
Another indication of the value of the tube at the upper end of the ventilation holes are clogged will also cause this failure. Solution; Repeated filtration of mercury to remove the oxidized mercury; cleaning of the tube; keep the ventilation holes open. Replace the leaky rubber ball, air tube or arm band; with the research valve cone surface, improve the contact condition, increase the contact surface so that the sealing is improved or replace the valve; carefully install the valve into the rubber ball;
Clear the valve rubber tube open seam at the dirty or replace it. When the sphygmomanometer unstable value, it must exist there are parts of the air leakage, but check out the parts of the air leakage is also a relatively numb
annoying, because the sphygmomanometer work pressure medium is air, the pressure is not high, but also pay attention to the mercury can not be overflowed, the more feasible and easy way to raise its pressure to 30kPa nearby,
the sphygmomanometer body together with the rubber bulb, the air tubing, the arm band Immersed in water, water can be submerged over the top of the mercury bottle, observation and found bubbling to the repair. The phenomenon of this failure is to close the exhaust valve, the use of rubber ball pressurized, the pressure is always on not go; or pinch the ball when the pressure went up, a release, the mercury column and down, or pressurized up, stop pressurizing, the mercury column falls very quickly.
Maintenance method is in the pressurized, respectively, folded and pressed from the rubber ball to the mercury storage bottle as well as from the mercury storage bottle to the arm with the airbag between the rubber tube, observe whether the mercury continues to fall, paragraph by paragraph to exclude find out the parts of the leakage. If the rubber bag leakage, should be replaced; if the rubber ball unit leakage, should check the ball end of the check valve or exhaust valve leakage, or should be replaced; if the rubber valve leakage, the rubber ball can be separated from the exhaust valve: screw buckle screwing type, unscrewing can see a small section of rubber tube similar to the bicycle tire valve core; toggle off the type, after removing the ball, you can also take out such a section of valve from the exhaust valve A section of the valve core, rubbing the rubber tube with your fingers, you can find a crack on each side, if the cracks in the lint filling, pressurization, release the ball, the cracks can not be closed, just hit on the mercury column will come down again. Clean up the dirt in the fissure, the resulting air leakage problem can be eliminated. The reason for this phenomenon:
After the sphygmomanometer is used, it is not tilted more than 450, so that the mercury flows back to the mercury storage bottle, resulting in a long time in contact with the mercury in the glass tube and air oxidation reaction occurs in the inner wall of the glass tube to generate black mercury oxide. When in use, because it is impossible to see clearly whether the convex surface of the mercury column in the glass tube is on the zero scale, resulting in errors in the sphygmomanometer's readings and affecting the accuracy of the measurement.
Handling method:
Remove the glass tube, screw a small cotton ball on one end of a long thin wire, the other end of the glass tube, pull the cotton ball to wipe the inside of the glass tube, such as in the case of stubborn stains can be dipped in the appropriate amount of alcohol. Should focus on cleaning with a mask to avoid inhaling black mercuric oxide powder.